Copending U.S. patent application Ser. No. 13/431,173, which is incorporated herein by reference, describes a machining apparatus comprising a frame defining first and second upper machining stations horizontally offset from each other and respective first and second lower transfer stations underneath the first and second upper machining stations. Respective first and second spindles have respective first and second workpiece grabs and are displaceable vertically on the frame between upper positions with the respective first and second grabs in the respective first and second machining stations and lower positions with the respective first and second grabs in the respective first and second transfer stations. Respective first and second workpiece conveyors extend through the first and second transfer stations for transporting workpieces into and out of the respective transfer stations so that the respective spindles can pick up unmachined workpieces from the respective transfer stations and set machined workpieces down in the respective transfer stations. A holder carries tools and is displaceable on the frame between the first and second machining stations so that while a workpiece is being machined by one of the tools in one of the machining stations a workpiece can be loaded into or unloaded from the grab of the spindle of the transfer station of the other of the machining stations. A chip deflector has first and second parts movable between respective catch positions underneath the respective first and second machining stations and respective parked positions not underneath the respective first and second machining stations such that, when the first and second parts are in their respective parked positions, the spindles are able to move vertically between the respective machining and transfer stations. A horizontal guide is provided on the frame along which the first and second parts of the chip deflector can travel in a straight line to move between the respective catch and parked positions.
Such a machine is relatively efficient, but the travel path of the workpiece between the work spindles is fairly long and complex.